In the general server box, the aperture specification of the coupling plate coupled with the drawer slideway is fixed. The slideway is always coupled with the box or the lateral portion of the cabinet by a screwing method. As a result, the drawer or the tray can be coupled with the slideway for the push-pull purpose. However, different coupling plates are provided with different specifications. In order to be suitable for boxes of different specifications, the slideways of different specifications must be provided. Accordingly, the conventional structure is short of convenience and is not suitable for use in the industry.